5.5 Stopping and Starting Multi-thread Programs

gdb supports debugging programs with multiple threads
(see Debugging Programs with Multiple Threads). There
are two modes of controlling execution of your program within the
debugger. In the default mode, referred to as all-stop mode,
when any thread in your program stops (for example, at a breakpoint
or while being stepped), all other threads in the program are also stopped by
gdb. On some targets, gdb also supports
non-stop mode, in which other threads can continue to run freely while
you examine the stopped thread in the debugger.